A cylinder head gasket is known in the art comprising a pair of gasket baseplates held sandwiched between a cylinder head and a cylinder block and having a combustion opening formed therein in alignment with a cylinder bore, a spacer disposed around the cylinder bore to surround it in an endless manner and held sandwiched between the pair of gasket baseplates and a full bead and/or half bead formed at a suitable location or locations on the gasket baseplates (Japanese Laid-Open Utility Model Application No. 71,865/1992 and Japanese Laid-Open Patent Application No. 165,167/1992).
In the prior art, when only gasket baseplates are provided which are formed with a full bead and a half bead, they are readily susceptible to the influence of any blowhole in the casting or flaw on mating adjoined surface, causing likelihood that the sealing performance becomes degraded.